licensing - Let's do the thing right:
 

I've spent couple of hours trying to understand how licensing works:
main point is of course the old good LGPL vs GPL software.
I would like to see if I get the right picture, and introduce who's unaware to some short explanation about licensing:
- Who uses GPLed sources for his projects has to distribute under gpl.
- Who uses LGPL can afterwards distribute under the same LGPL, increasing to GPL or pay for the commercial licensing for commercial distribution.
I'm right?
So couple of examples:
if I develop with QT, (lgpl) i should distribute my software for free under LGPL or GPL. If I'm willing to SELL it on OVI, or Android Market, there's no other way than paying for the commercial license.
If I use GPLed sources, i should provide them also with my sources code. And this is mandatory!!!

please some license guru, confirm or correct... 'couse I was dreaming about distributing for free the same app here and sell it for the Iphones. and this shall not be. (right?)

Re: licensing - Let's do the thing right:
 

One of the conditions of the GPL license that the source code must be made available publically (e.g. something like an ftp website or cdrom) - if you release the program publically.
You can charge as much as you like for the "binary" (e.g. the executable).
You can charge a nominal fee to distribute the source code if it is on a fixed media (e.g. tape or disk).
If you incorporate your own source code into GPL source code then your source code falls under the GPL license too.

The Lesser-GPL (LGPL) allow you to link things like your external libaries into a GPL-licensed program without your external library falling under the GPL.

QT is under a duel-license - GPL and QT-license.
If you write a gpl-license program under QT you do not have to pay any license fees.
If you write a closed-source program under QT a fee is payable.

That's how I understand things - best got advice from www.gnu.org licenses , faq
(I may visit it myself and make sure)

Re: licensing - Let's do the thing right:
 

Are you talking about modifying and redistributing GPL/LGPL code, or just writing your own app that uses GPL or LGPL libraries?

Qt is a bad example for illustration, it's available under GPL, LGPL and commercial licences so you can take your pick.

Re: licensing - Let's do the thing right:
 

As Qt doesn't work on the iPhone, have you thought about distributing your app as open source for non-iPhone platforms and as closed source for iPhone? Distributing the Qt "port" of your app as open source does not "infect" the iPhone version of your app with the same license (assuming that you wrote all the code yourself, you can decide under which terms you offer each port). That's how the author of Brain Party has done it (proprietary version for the iPhone with an open source port to Linux).

You can of course release your app closed-source for both Qt-based platforms and the iPhone - no problem there :)

Read that page and your questions shall be answered: http://qt.nokia.com/products/licensing/

(basically, with the LGPL'd version of Qt, you can have closed source code when you link to Qt dynamically IIRC - but IANAL)

Re: licensing - Let's do the thing right:
 

Just to clarify, because I think there was contradiction in previous posts.

Isn't Qt LGPL'ed, so if one makes commercial program which uses Qt and sells it, it is ok, free and one can choose whatever license one wants? Except, if the library (Qt) itself is developed futher and sold for example as Qt^2.

Re: licensing - Let's do the thing right:
 

The following are all ok (shorthand: GPL == GPLv3, LGPL == LGPLv2.1 in Qt context):

• Writing and distributing a closed-source app that's dynamically linked with Qt (using either a commercial or LGPL Qt licence).
  
• Writing and distributing a closed-source app that's statically linked with and/or includes Qt (using a commercial Qt licence).
  
• Writing and distributing an open-source app (any GPL/LGPL-compatible licence) that's dynamically linked with Qt.
  
• Modifying Qt for your own personal use (any Qt licence).
  

The following is not ok:

• Modifying and redistributing Qt with any licence other than GPL or LGPL.

Note also that source code licence and binary price are orthogonal, it's perfectly fine to sell GPL apps for $$$, as it is to give away closed-source binaries for free.

Re: licensing - Let's do the thing right:
 

thanks! this is exactly what I was looking for!!

so let's go to the second point:
What about the software ideas? the only way to protect them is patenting? or there's something else?ie: let's say that my app has e a new way to access the contacts, or a new way to handle emails. What could I do?

Re: licensing - Let's do the thing right:
 

Software patents cost an enormous amount of money and there is no guarantee you will get the patent.

Only large companies like Microsoft, Apple and Google can afford to patent their software algorithms and even then it depends how much a country will enforce them.

I imagine the cost of patenting an idea must run into thousands pounds.


Found this in a UK-based business forum:
Generally, Software patents are a "Bad Thing"

Re: licensing - Let's do the thing right:
 

Your code itself is automatically protected by copyright regardless of the licence (unless you explicitly place it in the public domain).

As for the ideas behind it, yes a patent would be the only way to restrict others from using them.

A software patent application may not be something you really want to go through though: it's not possible to get in many places, time consuming & expensive, and it may turn out that the required patent search (which in itself can be quite expensive as well) will turn up that your brand new idea actually has "prior art" implementations. Not to mention that many people believe software patents are evil ;-)

Note also that the GPLv3 has some additional requirements regarding patents, you should read them and understand them before deciding if it's suitable for your needs.

Re: licensing - Let's do the thing right:
 

wait.. I've just read in the GPL faqs that I can sell my crap, but if some of the buyers want to distribute it for free he can.
I feel kind of disappointed.. but ok...
so what is the best way to avoid getting my idea on "iphones" or on MS whatever?